Recent nmr studies which have provided new evidence for the catalysis of a number of reactions of amino and keto acids by vitamin B6 (pyridoxal or pyridoxamine, respectively) are being followed up by studies of reaction pathways by several methods. These techniques include effect of structure of substrate and catalyst on the kinetics and mechanism of reaction, variation of conditions required for optimization of reaction rates, and detection and isolation of intermediates. The relationship between these reactions and the metabolism of amino and keto acids in biological systems will be studied. The reaction types under investigation are: decarboxylation of alpha amino acids; catalysis of alpha-Beta carbon-carbon bond fission, elimination of electronegative substituents from Beta- and gamma- positions of alpha amino acids; mechanisms of racemization and its relationship to the mechanism of transamination; mechanism of formation of and isolation of transamination intermediates in metal chelate systems and metal-free systems; and the mechanism of catalysis of oxidative deamination of alpha amino acids by pyridoxal and transition metal ions. The relationship of the latter reaction to the metal- catalyzed insertion of oxygen to form pyridoxal oxime will be investigated. Information obtained on non-enzymic catalysis of reactions of molecular oxygen with amino acids by pyridoxal and metal ions will be applied to the interpretation of the mechanism of action of Cu(II)-containing amino acid oxidase enzymes. Reaction rates and mechanisms will be studied by following disappearance of reactant and growth and disappearance of intermediates and reaction products with the aid of proton and carbon nmr 13, circular dichroism, electronic spectrophotometry and Raman spectra. Equilibria will be determined by potentiometric and spectrophotometric techniques. Additional information on reaction pathways will be obtained by C14 and O18 labelling of reactants.